Bath-tub mold.



No 784,913. PATENTED MAR. 14, 1905. J. P. BIGKERSTAPP.

BATH TUB MOLD.

APPLICATION FILED DEC. 2, 1904.

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IYV E w 1 N m M m 7 l 0h w f H M f 4/7 m u 1 4 z INVENTOR ATTORNEY No. 784,913. PATENTED MAR. 14, 1905.

J. P. BICKBRSTAFF.

BATH TUB MOLD.

APPLICATION FILED DEG. 2, 1904.

3 SHEETSSHEET 2.

ATTORNEY PATENTED MAR. 14, 1905.

J. P. BIUKERSTAFP. BATH TUB MOLD. APPLICATION FILED DEG. 2, 19o4.

3 SHEETSSHEET 3.

INVENTOR ATTORNEY UNITED STATES Patented March 14, 1905.

PATENT OFFICE.

JAMES P. BICKERSTAFF, OF MONACA, PENNSYLVANIA, ASSIGNOR OF ONE- HALF TO SAMUEL MCGIVERN, OF MONACA, PENNSYLVANIA.

BATH-TUB MOLD.

SPECIFICATION forming part of Letters Patent No. 784,913, dated March 14, 1905.

Application filed D ber 2, 1904. Serial No. 235,154.

To all whom it may concern:

Be it known that I, JAMES P. BICKERSTAFF, a citizen of the United States, residing at Monaca, in the county of Beaver and State of Penn- 5 sylvania, have invented certain new and useful Improvements in Bath-Tub Molds; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which 10 it appertains to make and use the same, reference being had to the accompanying drawings, and to the figures of reference marked thereon, which form a part of this specification.

My invention relates to a new and useful improvement in bath-tub molds especially designed and constructed with a view of doing away with sand-molding, now commonly used in the manufacture of such articles.

By means of my improved method of cast- 20 ing bath-tubs. to be hereinafter more specifically described in detail, I am able to greatly reduce the cost of manufacture and materially increase the output over the present sandmolding method.

In the accompanying drawings, forming a part of this specification, I have illustrated my invention by several views, in which- Figure 1, Sheet 1,is aside elevation and partsectional view of my improved mold. Fig. 2, 0 Sheet 2, is an end and part-sectional view of the same. F ig. 3 is a cross-sectional view taken on line 3 3 of Fig. 1. Fig. 4, Sheet 3, is a horizontal sectional view taken on line 4 L of Fig. 1. Fig. 5 is a side view of the bottom plate used in the hollow-core casting, showing a vent-pipe in elevation. Fig. 6 is a plan view of said bottom plate, showing vent-openings therein.

Numerals of reference designate like parts throughout the several views, in which the numeral 1 designates upright supports forming the framework of the mold, 2 the base portion thereof, and 3 asupport or table having a central opening therein. Secured to this base portion 2 isa jack-screw 1, operated by a wheel 5. Connected to the top of the screw-stem 6 is a hollow cast-iron core or mold 7 used in forming the inside outline of the bath-tub. Through the bottom portion 8 of this inside mold are openings 9 and 10, whereby steam, gas, or any desired heat can be introduced into the chamber and exhausted therefrom. The ends of this bottom plate 8 are made bevel-shaped, so as to give a tight [it against the rim of the opening in the table 3 when the mold is pushed up into position.

Adjustably seated over the core-mold 7 is a hollow jacket 11, the inner face of which forms the outer face of the tub. Steam or any suitable heat is introduced into this hollow jacket through an opening 12 and permitted to escape through another opening, 13. A number of vent-openings 14. 14 are formed through the jacket 11 and communicate with the forming-chamber 15 between the inner and outer hollow molds.

A core 16 on the inner face of the jacket 11 will form the hole in the bottom of the tub through which the waste water escapes. Secured to the top of this outer hollow jacket 11 is a jack-screw 17, which is suspended from the top of the supporting-framework and operated by a wheel for the purpose of raising and lowering said jacket.

19 19 are metal gates placed at suitable intervals around the mold, each one communicating with a passage-way 20, formed by a groove in the top of the table 3, which in turn communicate with the forming-chamber 15.

An annular groove 21, formed around the rim of the opening in the table 3, Will form the beveled top of the completed tub and also serve as a seat for the same when the inner and outer forming-molds are removed.

In order to form the lugs on the bottom of the tub, to which are attached the feet, I provide a sand core 22 inserted in the inner face of the jacket 11.

In order to afford a means of escape for the gas generated in the forming-chamber 15 during the process of pouring, I provide a ventpipe 23 filled with sand, the lower end of which extends through the bottom portion 8 of the core 7 The top piece supporting the hoisting-jack 17 is hinged at one side of the frame, and by means of the rod 2 1 the outer jacket 11 may be lifted clear of the molded tub and the latter easily removed from its seat.

25 25 represent a locking device consisting of a rod formed on the ends of the jacket 11, which passes through an elongated slot in the projection '26 integral with the table 3. Allowance is thus made for the expansion of the jacket when it becomes heated, and at the same time it is held in position on the table.

In the operation of my improved method of molding bath-tubs the outer hollow jacket is first lowered by means of the adjustable screw 17 to its seat on the table 3, and the inner hollow core is likewise raised until it becomes firmly seated in the opening in the table. In this position there is left a space or chamber 15 between the outer and inner molds corresponding with the desired form of the bath-tub. Steam or any other form of heatsuch as gas, &c.is then introduced into the hollow core 7 through the opening 9 and a similar heating method into the outer hollow jacket 11 through the opening 12. As soon as both the core and jacket become sufficiently heated the metal is poured into the gates 19 until the forming-chamber 15 is entirely filled, the air or gas generated therein being forced out through the vents 14 and 23. The fact of having both core and jacket heated before the metal is poured into the moldingchamber will prevent the metal from shrinking, and in order to overcome any sticking of the'metal I give the walls of the forming-chamber a coat of paste especially prepared for that purpose. After waiting a few seconds until the metal has become thoroughly set and molded into the required shape the inner core 7 is screwed down and away from the newly-formed tub, thus permitting the required amount of shrinkage to take place during the cooling-off process. The outer jacket 11 is next screwed up and away from contact with the newly formed tub, which allows the latter to stand exposed and resting in the groove 21 until such time as it is desired to remove the same before preparing the mold for another pour.

It is apparent that slight changes may be made in the detail form of construction of my molding device without in any manner departing from the original idea or intention.

Having thus fully shown and described my invention, what 1 claim as new, and desire to secure by Letters Patent, is

1. A mold having a framework a supporting-table, an outer hollow jacket supported on said table, an inner core seating in an opening formed in the table and independent means for operating said core and jacket, said table being formed with an annular groove adjacent the opening therein, the groove being in communication with the space between the jacket and core.

2. A mold having a supporting-table, a hollow core seated in an opening formed in the table, an annular groove formed adjacent said opening, a hollow jacket seated over said core and supported by the table, gates leading to the space between the core and jacket, and vents to permit the escape of gas.

3. A mold having a supporting-table, ahollow core removably seated in an opening formed in said table, the table being formed adjacent said openingwith an annular groove, a hollow jacket removably seated over said core and supported by the table, the groove in the table being in communication with the space between the jacket and core, means for introducing a heating medium into the jacket and into the core, pouring-gates communicating with the space between the jacket and core, and vents for the escape of gas.

in testimony whereof I afiix my signature in presence of two witnesses.

JAMES P. BICKERSTAFF.

WVitnesses:

SAMUEL MGGIVERN, J. A. lnoNs. 

